<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <script>
        var array1 = new Array(7);
        console.log(array1.length);//7
        var array2 = new Array(100, 'a', true);
        console.log(array2.length);//3
        //构造一个空数组
        var array = new Array();
        array[0] = '123';
        console.log(array);//['123']
        console.log(array.length);//1
        array[1] = true;
        console.log(array);//['123', true]
        console.log(array.length);//2

        //JS中是数组可以不使用下标操作，push、pop往里面放数据拿出数据
        var arr = new Array();
        arr.push('zhangsan');
        console.log(arr);//['zhangsan']
        console.log(arr.length)//1
        arr.push(false);
        console.log(arr);//['zhangsan', false]
        console.log(arr.length)//2
        arr.push(56);
        console.log(arr);//['zhangsan', false, 56]
        console.log(arr.length)//3
        console.log(arr.pop());//56
        console.log(arr.pop());//false
        console.log(arr.pop());//zhangsan
    </script>
</body>
</html>